CERT(sm) Advisory CA-96.13
July 4, 1996
Topic: ID4 virus, Alien/OS Vulnerability
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The CERT Coordination Center has received reports of weaknesses in
Alien/OS that can allow species with primitive information sciences
technology to initiate denial-of-service attacks against MotherShip(tm)
hosts. One report of exploitation of this bug has been received.
When attempting takeover of planets inhabited by such races, a trojan
horse attack is possible that permits local access to the MotherShip
host, enabling the implantation of executable code with full root access
to mission-critical security features of the operating system.
The vulnerability exists in versions of EvilAliens' Alien/OS 34762.12.1
or later, and all versions of Microsoft's Windows/95. CERT advises
against initiating further planet takeover actions until patches
are available from these vendors. If planet takeover is absolutely
necessary, CERT advises that affected sites apply the workarounds as
specified below.
As we receive additional information relating to this advisory, we will
place it in
ftp://info.cert.org/pub/cert_advisories/CA-96.13.README
We encourage you to check our README files regularly for updates on
advisories that relate to your site.
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I. Description
Alien/OS contains a security vulnerability, which strangely enough
can be exploited by a primitive race running Windows/95. Although
Alien/OS has been extensively field tested over millions of years by
EvilAliens, Inc., the bug was only recently discovered during a
routine invasion of a backwater planet. EvilAliens notes that
the operating system had never before been tested against a race
with "such a kick-ass president."
The vulnerability allows the insertion of executable code with
root access to key security features of the operating system. In
particular, such code can disable the NiftyGreenShield (tm)
subsystem, allowing child processes to be terminated by unauthorized
users.
Additionally, Alien/OS networking protocols can provide a
low-bandwidth covert timing channel to a determined attacker.
II. Impact
Non-privileged primitive users can cause the total destruction of
your entire invasion fleet and gain unauthorized access to
files.
III. Solution
EvilAliens has supplied a workaround and a patch, as follows:
A. Workaround
To prevent unauthorized insertion of executables, install a
firewall to selectively vaporize incoming packets that do not
contain valid aliens. Also, disable the "Java" option in
Netscape.
To eliminate the covert timing channel, remove untrusted
hosts from routing tables. As tempting as it is, do not use
target species' own satellites against them.
B. Patch
As root, install the "evil" package from the distribution tape.
(Optionally) save a copy of the existing /usr/bin/sendmail and
modify its permission to prevent misuse.
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The CERT Coordination Center thanks Jeff Goldblum and Fjkxdtssss for
providing information for this advisory.
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If you believe that your system has been compromised, contact the CERT
Coordination Center or your representative in the Forum of Incident
Response and Security Teams (FIRST).
We strongly urge you to encrypt any sensitive information you send by email.
The CERT Coordination Center can support a shared DES key and PGP. Contact the
CERT staff for more information.
Location of CERT PGP key
ftp://info.cert.org/pub/CERT_PGP.key
CERT Contact Information
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Email cert@cert.org
Phone +1 412-268-7090 (24-hour hotline)
CERT personnel answer 8:30-5:00 p.m. EST
(GMT-5)/EDT(GMT-4), and are on call for
emergencies during other hours.
Fax +1 412-268-6989
Postal address
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
USA
CERT publications, information about FIRST representatives, and other
security-related information are available for anonymous FTP from
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CERT advisories and bulletins are also posted on the USENET newsgroup
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Copyright 1996 Carnegie Mellon University
This material may be reproduced and distributed without permission provided it
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CERT is a service mark of Carnegie Mellon University.